12131278 has 4 divisors (see below), whose sum is σ = 18196920. Its totient is φ = 6065638.

The previous prime is 12131269. The next prime is 12131293. The reversal of 12131278 is 87213121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87213121 = 29 ⋅3007349.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3032818 + ... + 3032821.

It is an arithmetic number, because the mean of its divisors is an integer number (4549230).

Almost surely, 2^12131278 is an apocalyptic number.

12131278 is a deficient number, since it is larger than the sum of its proper divisors (6065642).

12131278 is an equidigital number, since it uses as much as digits as its factorization.

12131278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6065641.

The product of its digits is 672, while the sum is 25.

The square root of 12131278 is about 3482.9984209012. The cubic root of 12131278 is about 229.7746879851.

Adding to 12131278 its reverse (87213121), we get a palindrome (99344399).

The spelling of 12131278 in words is "twelve million, one hundred thirty-one thousand, two hundred seventy-eight".